Prime Minister John Key said it wasn't a top priority for the Government to promote a Bill legalising adoption by gay couples.

Mr Key said he would vote for any Bill to progress to the Select Committee stage but would not confirm if he would vote for the bill to move further.

"My own personal opinion is the issue of gay adoption is not hugely significant issue and it's not because it doesn't matter to those couples who might want to adopt children, but the truth is less than 200 non-family adoptions take place in New Zealand at the moment.''

He said in the current economic climate it was not a priority for the Government.

National's Nikki Kaye and the Greens' Kevin Hague have joined forces to develop a bill that would legalise adoption by gay couples.

The National Party's northern regional conference in Auckland at the weekend passed a remit in closed session supporting adoption by couples in a civil union.

The party's national conference in July is expected to debate a gay adoption remit, although such a matter would be a conscience vote in Parliament.

It is possible that the Government could pick up the work Ms Kaye and Mr Hague are doing on adoption and surrogacy laws as a Government measure, while making some of the controversial issues a conscience vote.